[pve-devel] [PATCH v2 librados2-perl 1/7] mon_command: refactor to pass all data to perl

[Aaron Lauterer]

By passing back all return values from the Ceph API (RADOS.xs) to Perl
we are more flexible to make more than just the data available further
up the stack. These values are:

* return code
* status message (can contain useful information)
* data

The Ceph API interaction happens in a child process. We need to en- and
decode the returned hash in JSON to pass it between the child and parent
process.

RADOS.pm::mon_command now returns not just the data, but all information
as a hash ref.  Therefore dependent packages (pve-manager, pve-storage)
need to adapt.

Signed-off-by: Aaron Lauterer <a.lauterer at proxmox.com>
---
Make sure to coordinate breaking changes and releases of affected
packages: storager, manager
Patches 3 and 4 in this series contain the needed changes for these
packages

changes:
* simplify changes by always returning has href from RADOS.xs and handle
  errors in the Perl side (RADOS.pm).
* always return hash ref from RADOS.pm::mon_command()


 PVE/RADOS.pm | 20 ++++++++++++++++----
 RADOS.xs     | 18 ++++++------------
 2 files changed, 22 insertions(+), 16 deletions(-)

diff --git a/PVE/RADOS.pm b/PVE/RADOS.pm
index 463abc7..bec5028 100644
--- a/PVE/RADOS.pm
+++ b/PVE/RADOS.pm
@@ -201,7 +201,7 @@ sub new {
 	    my $res;
 	    eval {
 		if ($cmd eq 'M') { # rados monitor commands
-		    $res = pve_rados_mon_command($self->{conn}, [ $data ]);
+		    $res = encode_json(pve_rados_mon_command($self->{conn}, [ $data ]));
 		} elsif ($cmd eq 'C') { # class methods
 		    my $aref = decode_json($data);
 		    my $method = shift @$aref;
@@ -265,13 +265,25 @@ sub mon_command {
 
     my $json = encode_json($cmd);
 
-    my $raw = eval { $sendcmd->($self, 'M', $json) };
+    my $ret = $sendcmd->($self, 'M', $json);
     die "error with '$cmd->{prefix}': $@" if $@;
 
+    my $raw = decode_json($ret);
+
+    die "error with '$cmd->{prefix}': mon_command failed - $raw->{status_message}\n"
+	if $raw->{return_code} < 0;
+
+    my $data = '';
     if ($cmd->{format} && $cmd->{format} eq 'json') {
-	return length($raw) ? decode_json($raw) : undef;
+	$data = length($raw->{data}) ? decode_json($raw->{data}) : undef;
+    } else {
+	$data = $raw->{data};
     }
-    return $raw;
+    return {
+	return_code => $raw->{return_code},
+	status_message => $raw->{status_message},
+	data => $data,
+    };
 }
 
 
diff --git a/RADOS.xs b/RADOS.xs
index 9afba1c..45f634c 100644
--- a/RADOS.xs
+++ b/RADOS.xs
@@ -98,7 +98,7 @@ CODE:
     rados_shutdown(cluster);
 }
 
-SV *
+HV *
 pve_rados_mon_command(cluster, cmds)
 rados_t cluster
 AV *cmds
@@ -136,18 +136,12 @@ CODE:
         &outslen
     );
 
-    if (ret < 0) {
-        char msg[4096];
-        if (outslen > sizeof(msg)) {
-            outslen = sizeof(msg);
-        }
-        snprintf(msg, sizeof(msg), "mon_command failed - %.*s\n", (int)outslen, outs);
-        rados_buffer_free(outs);
-        rados_buffer_free(outbuf);
-        die(msg);
-    }
+    HV * rh = (HV *)sv_2mortal((SV *)newHV());
 
-    RETVAL = newSVpv(outbuf, outbuflen);
+    (void)hv_store(rh, "return_code", 11, newSViv(ret), 0);
+    (void)hv_store(rh, "status_message", 14, newSVpv(outs, outslen), 0);
+    (void)hv_store(rh, "data", 4, newSVpv(outbuf, outbuflen), 0);
+    RETVAL = rh;
 
     rados_buffer_free(outbuf);
     rados_buffer_free(outs);
-- 
2.30.2